Simultaneous dyeing and bleaching of proteinaceous fibrous material



United States Patent Ofilice 3,551,087 Patented Dec. 29, 1970 US. Cl.8-19 9 Claims ABSTRACT OF THE DISCLOSURE Process for simultaneouslydyeing and bleaching a proteinaceous fibrous material in which thefibers art. treated at an elevated temperature as required for dyeingwool in a neutral or acid aqueou liquor containing (a) an acid dyestable to peroxides, (b) performic acid which is preferably being formedin said liquor during the treatment, and (c) an oxygen stabilizer.

Proteinaceous fibrous material, such as animal hair, particularly wooland silk, fiber mixtures containing the same and materials preparedtherefrom, are as a rule dyed at elevated temperature, i.e. at 80 to 100C. or under superatmospherie pressure at abov 100 C. in nonalkalineliquors: the liquors generally contain conventional so-called wool dyesand may optionally contain dyeing assistants. for example levelingagents.

It is often necessary or desirable to bleach the proteinaceous fibrousmaterial so that the dyes may have full action. it has hitherto beencustomary to carry out the said bleaching in alkaline liquors whichcontain about 3 to 10 g./l. of 100% hydrogen peroxide, equivalent toabout 1.5 to g./l. of active oxygen, and a peroxide stabilizer, forexample an alkali metal pyrophosphate or a complex-formingpolyphosphate.

Since a neutral to acid medium is required for the dyeing of wool withso-called wool dyes, the two operations of bleaching and dyeing cannotbe carried out at the same time in the same liquor. Simultaneousbleaching and dyeing, however. would be very desirable because thetreatment of the wool could be greatly simplified in this manner.

It is, therefore, an object of this invention to provide a method ofbleaching and dyeing protcinaceous fibrous material in a particularlysimple way in one operation. It is a further object of the invention toprovide a process in which the active oxygen which causes the bleachingbecomes available gradually during the reaction period. Further objectswill be apparent from the description.

These objects, namely a process for the simultaneous dyeing andbleaching of proteinaeeous fibrous material, particularly silk and wool,are achieved by treating the proteinaceous fibers with a non-alkalineaqueous dye liquor which contains (a) a so-called acid wool dye" whichis an acid dycstuff capable of dyeing wool and which must also bestableto peroxides, and (b) pcrformic acid formed, preferably in situ, byreaction of hydrogen peroxide with a substance capable of splitting offformaldehyde under the reaction conditions, a low molecular weightformic acid alkanol ester and/or a low molecular weight formaldehyde,0.2 to 10 grams/liter, preferably 0.5 to 2 grams/liter, of active oxygenbeing made available in the dye liquor during the treatment of thefibers. A conventional peroxide stabilizer, also referred to as anoxygen stabilizer, is also used in the non-alkaline aqueous liquor.

We mean by active oxygen, oxygen which is set free from hydrogenperoxide when it is converted quantitatively to water.

Substances yielding formaldehyde are defined as substances which containat least once a group having the general formula:

Y-CH X (I) in which Y denotes a nitrogen or oxygen atom, X denotes anitrogen or oxygen atom or the group --SO M in which M is a proton, anammonium ion, an alkali metal ion or half an alkaline earth metal ion,and the valencies of the said nitrogen and/or oxygen atoms which are notattached to the central carbon atom being, in the absence of a 50 Mgroup, at the most partly saturated by hydrogen.

Examples of substances which contain at least once a group having theFormula I are: formaldehyde polymers, such as trioxymcthylene,tetraoxymethylene and paraformaldchyde; low molecular weight formals,such as dimethylformal and diethylformal hydroxymcthanesulfonic acid;aminomcthanesulfonie acid; imino-bis-methanesulfonic acid and lowmolecular weight N-alkyl and N-hydroxyalkyl derivatives of these twoacids; nitrolotrismethanesulfonic acid, alkali metal salts and alkalineearth metal salts of these acids, such as preferably the sodium,potassium and calcium salts; N-methylol compounds of carbamides, such asparticularly urea, imidazolincs, tetrahydrotriazinones,hexahydropyrimidones and urones; of mclamincs, of dicyanodiamide; andalso ethers of such N-methylol compounds with alcohols having one tofive carbon atoms.

Examples of low molecular weight formic alkanol esters and formamidesare substances having the general formula Q (it) in which Q denotes aradical OR or R being an alkyl radical having one to five carbon atoms,R being a hydrogen atom or an alkyl radical having one to five carbonatoms and R being a hydrogen atom or an alkyl radical having one to fivecarbon atoms. Examples of substances having the Formula II are: methylformate, ethyl formate, propyl formate, butyl formate anddiethylformamide.

The term "low molecular weight in the present application meanscompounds which contain no alkyl groups or contain alkyl groups havingone to five carbon atoms.

Particularly advantageous results are obtained when the substances whichsplit off formaldehyde or low molecular weight formamides used oradditionally used are those which form ammonia or amines by reactionwith hydrogen peroxide. This feature results in the drop in the pH ofthe dye-bleach liquor otherwise occurring during simultaneous dyeing andbleaching owing to the formation of formic acid being either preventedor minimized. In this manner optimum dyeing and bleaching conditions interms of a specific pH range are always maintained. A particularlysuitable and therefore preferred substance of this type ishcxamethylenetetramine. Formamide, dimethylformamide,aminomethanesulfonic acid, imino-bismcthanesulfonic acid, andderivatives bearing alkyl radicals at the nitrogen atoms, particularlythe methyl derivatives and the salts, however, act in the same way.

Substances of the abovementioned type are reacted with hydrogen peroxidein aqueous medium. The speed of this reaction is dependent on thehydrogen ion concentration of the medium. An acid or neutral range isused to achieve rapidly a bleaching solution which is ready for use. Theacid reaction may be produced by adding inorganic or organic acids oracid salts. The acids may be chosen at will. Strong acids are verysuitable, such as sulfuric acid and sulfonie acids, and acid salts suchas sodium bisulfite and sodium bisulfate. The amount of acid substancerequired depends on its acidity. Amounts of 0.5 to of strong acids, withreference to the weight of hydrogen peroxide to be reacted, areadequate, whereas 10 to 50% of weaker acids or acid salts may benecessary. It seems as though even in acid solution, the reaction toform performic acid does not immediately proceed to the point ofcompletely exhausting one reaction component; possibly an equilibriumcondition is set up which continues during bleaching and consequentlyduring consumption of performic acid, as long as all the reactants arestill present.

The ratio between (a) formaldehyde as obtained from compounds which arecapable of splitting otf formaldehyde, low molecular weight formic acidalkanol esters or low molecular weight formamides, and (b) hydrogenperoxide is preferably chosen so that for each mole of said esters andamides or each mole of formaldehyde available from the compoundssplitting off formaldehyde, 1 to 12 moles of hydrogen peroxide isavailable; particularly successful results are achieved with a molarratio of (a):(b) falling within a range of about 1:3 to 1:10.

The amount of hydrogen peroxide depends on whether it is desired tobleach in a long liquor or with a padding liquor. Amounts of 35%hydrogen peroxide of from l0 to ccm./l have proved to be particularlyuseful for long liquors and from 40 to 130 ccm./l for padding liquors.

The performic acid may be prepared by adding the ingredients, in theamounts desired for bleaching, direct to the liquor which alreadycontains dye and dyeing assistants. Altcrnatively a concentrated stockbleaching solution may first be prepared which is diluted to the finalconcentration shortly prior to use or added in the necessary amount tothe liquor containing dye and dyeing assistants. Stock bleachingsolutions may be prepared in concentrations which are equivalent to 100to 500 ccm./l of hydrogen peroxide. When preparing stock bleachingsolutions it is recommended that the temperature should not exceed C;bleaching liquors to which the ingredients are added direct may howeverbe prepared at higher temperatures, i.e. temperatures up to about 60 C.

For simultaneous dyeing and bleaching according to the presentinvention, liquors are required which contain conventional oxygenstabilizers. It is advantageous to add these stabilizers dttring theformation of the performic acid. The following may be given as examplesof stabilizers which may be used alone or mixed together: magnesiumsilicate, magnesium phosphate, prefsolid acids or acid salts, forexample citric acid, tartaric erably polymerized chain phosphates havingthe general formula: M P O in which M denotes the radical of an alkalimetal, particularly of: sodium or potassium, and n denotes one of theintegers from 2 to 10, such as tetra-alkali pyrophosphatcs, alkalitripolyphosphates and more highly condensed phosphates, such as alkalimetal tetrapolyphosphates, to hcptapolyphosphatcs, and particularlycomplex-forming aminopolycarboxylic acids, especially those having thegeneral formula:

Clh-COOll in which Z denotes the radical -CH COOH or A denotes a radicalhaving the formula:

Kent-anon)...

m denotes one of the integers zero, 1 or 2 and Y denotes a radicalhaving the formula such as N hydroxyethylethylenediaminetriacetic acid.o-cyclohcxylenediaminctetracetic acid, diethyicnetriamincpentaaceticacid, triethylenetetraminehexaacetic acid, N-hydroxyethyldiethylenetriaminctetraacetic acid and particularlynitrilntriacctic acid and ethylencdiaminetetraacetic acid and theammonium, magnesium, alkali metal and alnaline earth metals salts,particularly the magnesiumsodium, magnesium-potassium, sodium andpotassium salts of these acids. The said phosphates have only arelatively slight stabilizing effect in the said method and they aretherefore used in large amounts, i.e. twice to thirty times, preferablythree to fifteen times the weight of active oxygen available.Complex-forming aminopolycarboxylic acids or their salts of theabovementioncd types are therefore preferred as stabilizers; 0.1 toonce, preferably 0.25 to 0.5 the weight of active oxygen available isenough of these stabilizers. Particularly good results are oftenachieved with mixtures of complex-forming aminopolycarboxylic acids rtheir salts and the said phosphates. These mixtures may be used in thesame small amounts as the complex-forming aminopolycarboxylie acids andoften give a better bleaching effect than the said substances alone.

The production of performic acid is particularly convenient andadvantageous when, a stable composition is prepared which contains inthe correct proportions the components which in water with hydrogenperoxide will give a bleaching liquor ready for use. A particularlyadvantageous stock composition of this type contains 50 to 20% by weightof hexamethylenc tctramine, 30 to 60% by weight ofhydroxymethanesulfonic acid or its ammonium, alkali metal (particularlysodium or potassium), or alkaline earth (particularly calcium) salts, 10to 17% by weight of polytneric linear alkali metal phosphates,particularly sodium or potassium phosphates, and 10 to 3% by weight ofethylencdiaminotetraacetic acid or its ammonium, alkali metal(particularly sodium or potassium), or alkaline earth metal(particularly magnesium) salts. Moreover the composition may containacid, sodium hydrogen sulfate and potassium hydrogen phosphate. Such acomposition may be used for example as follows: for each liter ofbleaching liquor, 20 ccm.

lleC

of 35% hydrogen peroxide is mixed with 20 ccm. of

water, 3 to 7 g. of the composition is dissolved therein and thesolution is made up to 1 liter with water.

Performic acid obtainable in accordance with the directions given abovemay be added to the dye liquor in the form of solutions of anyconcentration, if it is not prepared from the start in the dye liquor.Since performic acid decomposes readily, it is recommended not toprepare it until shortly before it is to be used.

The new method may be applied very simply. As in prior art dyeingmethods, the working conditions are adapted particularly to thedyesbeing used. In particular the pH value of the liquor, which is usuallyfrom 1 to 7, is chosen to provide those conditions especially favourablefor the particular dye or dyes. In contrast to conventional dyeingmethods, there is only one restriction, namely that wool dyes which areresistant to peroxides must be used. Dye manufacturers give details ofthe behavior of their dyes with respect to peroxides in their patterncards or other technical literature. In other respects, the dyes usedmay belong to the conventional classes for wool dyeing. In general,"acid wool dyes" are used for the process of the invention, for instancethe dyes listed as "acid dyes in the Colour Index 1956, 2nd edition, andmarked as being suitable for dyeing wool. Acid azo dyes, acidanthraquinone dyes, 1:1 metal complex dyes and 1:2 metal complex dyesmay be given as examples of the most important classes. In addition topcrformic acid, the dye or dyes and agents for regulating the pH value,the liquors may contain the conventional assistants for dyeingproteinaceous fibrous material, for example leveling agents, wettingagents, carriers, dispersing agents, buffer salts, neutral salts andfiber protectives.

Working with bleaching dye liquors prepared in accordance with the abovestatements is analogous to conventional dyeing of proteinaceous fibrousmaterial. Thus for example the material to be treated may be added tothe liquor heated to about 50 C., the liquor heated to boiling point andkept at boiling temperature for about one hour. It is also possible touse the high-temperature method, i.e. to carry out the treatment underpressure at temperatures above 100 C. with a corresponding shortening ofthe treatment time. Another possibility, particularly suitable for topsand piece goods, is continuous dyeing and bleaching by padding andsteaming. The dyed and bleached material is rinsed hot and cold in theusual way. Further processing of the treated material is as usual.

If the combined dyeing and bleaching liquor is to be used only once itis advantageous economically to choose a content of bleaching agentwhich is not too high. Amounts of bleaching agent corresponding to 0.5to 2 g./l. of active oxygen have been found to be adequate. There ishowever also the possibility of using one and the same liquor severaltimes, the amounts of dye and chemical reagents which have been used upbeing replenished. In this so-called standing bath method, it ispossible to use the same liquor six to eight times.

The present process may also be combined with other wet finishingmethods, in the treatment of wool and wool mixtures, for example, with abrightening or an antifelt finishing by chlorination. It is easilypossible to carry out all these treatments in the same liquor.Brightening in the same liquor is preferably carried out during thebleaching and dyeing or after the same. For the antifelt finish, theliquor may first be charged for example with clementary chlorine orsubstances yielding chlorine, such as dichlorocyanuric acid or itssalts, particularly alkali metal salts, such as sodium and potassiumsalts, substances for regulating the pH value, anti-swelling agents andthe like and, following the treatment of the fibrous material withchlorine, which usually takes place at room or slightly elevatedtemperature, the abovementioned substances for bleaching and dyeing areadded to the same liquor. Then at the same time, without the additionalmeasures otherwise conventionally used, an oxidizing antichlorinationtakes place, i.e. the unused chlorine is rendered innocuous. A furthersimplification is possible by carrying out the chlorine treatment andthe bleaching and dyeing at the same pH value. The pH value may beadjusted for all steps of the process prior to the commencement of thechlorine treatment.

The advantages of the new process lie in a considerable shortening andsimplification of the course of the treatment.

The invention is illustrated by the following examples.

EXAMPLE 1 100 kg. of washed loose wool is pressed in the usual way intothe material carrier of an alloyed steel pack dyeing machine which holdsabout 1,000 liters of liquor. The machine is first filled with about 900liters of water and circulation is commenced in order to expel the bulkof the air from the woolen material. Then 10 liters of 35% hydrogenperoxide is added and then 3 kg. of a mixture of:

Parts Sodium hydroxymethanesulfonate 56 Hexamethylene tetramine 23Sodium tripolyphosphate 1 Ethylenediaminotetracetic acid '6 is dissolvedin the liquor. The liquor is heated to 50 C., 10 kg. of anhydrous sodiumsulfate and 8 kg. of ammonium acetate are added and the whole is made upto about 1,000 liters. 50 g. of the dye C.I. Acid Blue 59 (C.I. 50,315)is dissolved in a little water and added to the liquor. The liquor isheated to boiling temperature in about thirty minutes and left atboiling temperature for forty to forty-five minutes. Then 1.5 liters of60% acetic acid is added and the whole again left at boiling temperaturefor twenty-five to thirty minutes. The goods are then rinsed with waterin the usual way. A pale blue dyeing is obtained which is just asbeautiful and bright as when the goods have been bleached prior todyeing.

After dyeing is over, the liquor may be removed and after appropriatereplenishment with active oxygen, i.e. with hydrogen peroxide and theabovementioned mixture, dye and other additives, may be used for one ormore further dyeing batches.

EXAMPLE 2 An alloyed steel dyeing machine for tops bobbins is used whichholds 1,500 liters of liquor. About 1,250 liters of water is firstintroduced into the machine and then the bobbins with 100 kg. ofunbleached wool tops are introduced. With the circulation pump running,the water is heated to about 50 C. and then 1 liter of 60% acetic acidin added and also 15 liters of 35% hydrogen peroxide, 2.2 kg. of sodiumiminobismcthancsulfonate, 1.1 kg. of hexnmcthylene tetramine, 0.5 kg. ofethylenediaminotetracetic acid and 0.5 kg. of sodium pyrophosphate. ThepH value is adjusted to about 4.5 with acetic acid. 250 g. of the sodiumsalt of the acid sulfuric acid ester of an adduct of 1 mole of sperm oilalcohol and moles of ethylene oxide and 400 g. of an adduct of 1 mole ofoleylamine and 10 moles of ethylene oxide are added as a leveling agentand then g. of the dye C.I. Acid Blue 62 (C.I. 62,045) which haspreviously been dissolved in water. The liquor is then made up to 1,500liters with Water. It is heated to boiling point in about fifteenminutes and left at the boiling temperature for one hour. The goods arerinsed with water in the usual way. A pale blue dyeing is obtained whichis just as beautiful and bright as on previously bleached goods.

EXAMPLE 3 and the circulation pump is switched on, in order to expel thebulk of the air from the cheeses. 20 liters of 35% hydrogen peroxide and6 kg. of a mixture of Parts Sodium nitrilomethanesulfonate n--. 50Hcxamethylene tetramine 20 Ethylcnediaminotetracctic acid 10 Sodiumtripolyphosphate 20 are dissolved in the liquor. The liquor is thenheated to about 50 C., 25 kg. of anhydrous sodium sulfate and 20 kg. ofammonium acetate are added and the whole is made up to 2,500 liters withwater. 375 g. of the dye C.I. Acid Blue 90 (Cl. 42,655) is dissolved inwater and added to the liquor, which is then heated to boilingtemperature within twenty to thirty minutes and kept at this temperaturefor forty to forty-five minues. 3.7 liters of 60% acetic acid is addedand dyeing is continued for another twenty to thirty minutes at theboiling temperature. The material is then rinsed in the usual way. Abright pale blue dyeing is obtained which is just as beautiful andbright as on previously bleached material.

The exhausted liquor may be appropriately replenished with activeoxygen, i.e., with hydrogen peroxide and the abovementioned mixture. dyeand other additives and used again for one or more further batches fordyeing.

EXAMPLE 4 The procedure of Example 3 is followed with the exception thatwith the 25 kg. of anhydrous sodium sulfate there is added to theinitial water 12 kg. of concentrated sulfuric acid instead of the 20 kg.of ammonium acetate. 250 g. of CI. Acid Blue 45 (Cl. 63,010) is usedinstead of Cl. Acid Blue 90.

EXAMPLE 5 About 1,800 liters of water is placed in an alloyed steelsuspension machine which will hold 2,000 liters of liquor, and liters of35% hydrogen peroxide and 3 kg. of a mixture of:

Parts Trioxymethylcne 57 Sodium iminomethanesulfonate 20 Sodiumpyrophosphate Ethylenediaminotetraeetic acid 8 are dissolved therein.1.5 kg. of 60% acetic acid and 0.5 kg. of the sodium salt of the acidsulfuric acid ester of an adduct of 1 mole of sperm oil alcohol and 80moles of ethylene oxide are added and the whole is made up to 2,000liters with water. 200 g. of the dyez Oil 110 lhNOsS in the form of its1:2 chromium complex is dissolved in water and added to the liquor andwhile the latter is being circulated continuously, the material carrier,on which 100 kg. of unbleached precleaned woollen yarn is suspended, isintroduced into the liquor. The liquor is brought to boiling temperaturewithin forty to forty-five minutes and then dyeing carried out for fortyto fortyfive minutes at the boiling temperature. The material is thenrinsed with water in the usual way. A beautiful pale violet dyeing isobtained which is just as bright as on previously bleached yarn.

EXAMPLE 6 100 kg. of precleaned woollen yarn is chlorinated in thefollowing way in an alloyed steel suspension machine Ill) dissolved inthe wetting liquor, then a previously prepared solution of 2.5 kg. ofanhydrous tetrasodium pyrophospate and 4 kg. of potassiumdichloroisocyanurate in about 50 to 60 liters of water is added to theliquor which is adjusted with acetic acid to a pH value of about 5. Thematerial carrier is then reintroduced and the yarn is chlorinated forthirty to sixty minutes at 10 to C. with the circulation pump running.If the active chlorine present is not being absorbed quickly enough bythe wool, the temperature may be raised to to C. for ten to fifteenminutes before the end of the chlorination.

8 kg. of ammonium acetate, 15 liters of hydrogen peroxide and 4.5 kg. ofthe mixture according to Example 1 are then added to the same liquor.Heating up of the liquor is then commenced and an aqueous solution of g.of C.I. Acid Blue 59 (CI. 50,315) is added at once. Boiling temperatureis reached in thirty minutes and this temperature is maintained forforty to forty-five minutes. Then 1.5 liters of 60% acetic acid is addedand dyeing is completed in another twenty to thirty minutes. The dyedyarn is rinsed with water in the usual way and the material carrier iswithdrawn from the machine.

A non-felted, creaseproof yarn having a pale blue color. whosebrightness is equivalent to that of a dyeing on a separately bleachedyarn, is obtained in one and the same liquor.

EXAMPLE 7 About 900 liters of water is placed in an alloyed steel winchdyeing machine having a liquor capacity of 1,000 liters. and 0.75 literof 60% acetic acid, 1 kg. of ammonium sulfate and 125 g. of the sodiumsalt of the acid sulfuric acid ester of an adduct of 1 mole of sperm oilalcohol and moles of ethylene oxide are dissolved therein. 5 liters of35% hydrogen peroxide, 0.8 kg. of dimethylolurea, 80 g. of hexamcthylcnetctramine. g. of sodium bisulfitc. 270 g. of sodium bisulfate, 150 g. ofsodium pyrophosphatc and g. of ethylene diaminotetracctic acid aredissolved in the liquor. Finally 50 g. of the dye having the formula:

innois N=1lz i OCll';

is dissolved in water and added to the liquor and the liquor is made upto a total of 1,000 liters with water. 50 kg. of unbleached precleanedwoollen piece goods is then introduced into the liquor, ten minutes isallowed to elapse for wetting of the materiahand the liquor is thenheated to boiling temperature within forty to forty-five minutes andkept at boiling temperature for another forty to forty-five minutes. Theliquid is then drained off and the material is rinsed in the usual way.A beautiful pale grey dyeing is obtained.

EXAMPLE 8 100 kg. of washed loose wool is pressed in the usual way intothe material carrier of an alloyed steel pack dyeing machine having acapacity of about 1,000 liters of liquor. The machine is first filledwith about 900 liters of water and the circulation is switched on inorder to expel the bulk of the air from the wool. liters of 35% hydrogenperoxide, 0.45 kg. of sodium tripolyphosphate and 0.18 kg. ofethylenediaminotetracetic acid are added and 1.5 liters of 10% sulfuricacid and 1 liter of formamide are dissolved in the liquor. The liquor isthen heated to 50 C., 10 kg. of anhydrous sodium sulfate and 8 kg. ofammonium acetate are added and the whole is made up to about 1,000liters with water. 50 g. of the dye C.I. Acid Blue 59 (C.I. 50,315) isdissolved in a little water and added to the liquor. The liquor isheated to boiling temperature within about thirty minutes and left atboiling temperature for forty to forty-five minutes. 1.5 liters of 60%acetic acid is then added and the whole left at boiling temperature foranother twentyfive to thirty minutes. The material is then rinsed in theusual way. A pale blue dyeing is obtained which is just as beautiful andbright as when the material has been bleached prior to dyeing.

When dyeing is over, the liquor may be removed and used again for one ormore further dyeing batches after it has been appropriately replenishedwith active oxygen, i.e., with hydrogen peroxide and formamide, dye andconventional additives.

EXAMPLE 9 An alloyed steel dyeing machine [or tops bobbins is used whichhas a capacity of 1,500 liters of liquor. About 1,250 liters of water isfirst placed in the machine and the bobbins are introduced with 100 kg.of unbleached wool tops. With the circulation pump running, the liquoris preheated to about 50 C. and then 1 liter of 60% acetic acid, 0.5 kg.of ethylenediaminotetracctic acid and 0.5 kg. of sodium polyphosphateare added together with 22.5 liters of a stock bleaching solutionprepared previously from liters of 35% hydrogen peroxide 2.3 liters of10% sulfuric acid and 5.2 liters of dimethylformamide.

The pH value is adjusted to about 4.5 with acetic acid. 250 g. of thesodium salt of the acid sulfuric acid ester of an adduct of 1 mole ofsperm oil alcohol and 80 moles of ethylene oxide and 400 g. of an adductof 1 mole of oleylamine and 10 moles of ethylene oxide are added as aleveling agent and then 100 g. of the dye C.I. Acid Blue 62 (C.I.62,045) which has previously been dissolved in water. The liquor is thenmade up to 1,500 liters with water. The liquor is heated up to boilingpoint in about fifteen minutes and left at boiling temperature for onehour. A pale blue dyeing is obtained which is just as beautiful andbright as on a previously bleached material.

EXAMPLE 10 About 2,250 liters of water is placed in an alloyed steelcheese dyeing machine having a capacity of about 2,500 liters of liquor,the material carrier with 250 kg. of precleaned woolen yarn in the formof cheeses is introduced and the circulation pump is switched on, inorder to expel the bulk of the air from the cheeses. Then 0.6 kg. ofethylenediaminotetracetic acid, 1.2 kg. of sodium tripolyphosphate and30 liters of a stock bleaching solution according to Example 9 are addedto the liquor, the liquor is heated up to about 50' C., 25 kg. ofanhydrous sodium sulfate and kg. of ammonium acetate are added and thewhole is made up to 2,500 liters with water. 375 g. of the dye C.I. AcidBlue 90 (C.I. 42,655) is dissolved in water and added to the liquor. Thewhole is heated to boiling temperature within twenty to thirty minutes,kept at this temperature for another forty to forty-five minutes, 3.7liters of 60% acetic acid is added and dyeing is continued at theboiling point for another twenty to thirty minutes. The material is thenrinsed in the usual way. A pale blue dyeing is obtained which is just asbeautiful and bright as on previously bleached material.

10 The exhausted liquor may be appropriately replenished with activeoxygen, i.e. with the stock bleaching solution according to Example 9,dye and other additives and used again for one or more further dyeingbatches.

EXAMPLE 11 The procedure of Example 10 is followed with the differencethat 12 kg. of concentrated sulfuric acid is added to the liquor insteadof 20 kg. of ammonium acetate, and 250 g. of C.I. Acid Blue 45 (C.I.63,010) is used instead of C.I. Acid Blue 90.

EXAMPLE 12 About 1,800 liters of water are placed in an alloyed steelsuspension machine which will hold 2,000 liters of liquor and 0.45 kg.of sodium pyrophosphate, 0.24 kg. of ethylenediaminotetracetic acid and16.5 liters of a stock bleaching solution formed from Parts 35% hydrogenperoxide 60 Water 35 10% sulfuric acid 2 Methyl formate 3 is dissolvedtherein. 1.5 kg. of 60% acetic acid and 0.5 kg. of the sodium salt ofthe acid sulfuric acid ester of an adduct of 1 mole of sperm oil alcoholand moles of ethylene oxide are added and the whole made up to 2,000liters with water. 200 g. of the dye in the form of its 1:2 chromiumcomplex used in Example 5 is dissolved in Water and added to the liquorand while the latter is being circulated, the material carrier carryingkg. of unbleached precleaned woolen yarn is introduced into the liquor.The liquor is heated to boiling temperature in forty to forty-fiveminutes and dyeing is carried out for another forty to forty-fiveminutes at the boiling temperature. The material is then rinsed withwater in the usual way. A pale blue dyeing is obtained on the woolenyarn which is just as bright as on previously bleached yarn.

EXAMPLE 13 100 kg. of precleaned woolen yarn is chlorinated in thefollowing way in an alloyed steel suspension machine which will hold1,500 liters of liquor.

Prewetting is carried out for about ten minutes with 0.2 kg. ofnonylphenol octaglycol ether in about 1,500 liters of cold water at 10to 20 C. The material carrier is then withdrawn, 10 kg. of anhydroussodium sulfate is dissolved in the wetting liquor, then a previouslyprepared solution of 2.5 kg. of anhydrous tetrasodium pyrophosphnte and4 kg. of potassium dichloroisocyanate in about 50 to 60 liters of wateris added to the liquor which is then adjusted to a pH value of about 5with acetic acid. The material carrier is then again introduced and theyarn is chlorinated at 10 to 20 C. for thirty to sixty minutes with thecirculation pump running. If the active chlorine present is absorbed tooslowly by the wool, the temperature may be raised to 25 to 30 C. for tento fifteen minutes toward the end of the chlorination.

Then 0.675 kg. of sodium tripolyphosphate, 0.27 kg. ofcthylencdiaminotetracetic acid, 8 kg. of ammonium acetate, 15 liters of35% hydrogen peroxide, 2.3 liters of diethylformamide and 3.5 liters of10% sulfuric acid are added to the same liquor. Heating up of the liquoris then commenced and an aqueous solution of 50 g. of C.I. Acid Blue 59(C.I. 50,315) is added at once. The liquor is heated up to boilingtemperature in thirty minutes and left at heating temperature for fortyto forty-five minutes. Then 1.5 liters of 60% acetic acid is added anddyeing is completed in another twenty to thirty minutes. The dyed yarnis rinsed in the usual way with water and the material carrier isremoved from the machine.

A non-felted, creaseproof yarn having a pale blue dyeing wherebrightness is equivalent to that of a dyeing on sepa- 1 1 ratelybleached yarn is thus obtained in one and the same liquor.

EXAMPLE 14 About 900 liters of water is placed in an alloyed steel winchdyeing machine having a liquor capacity of 1,000 liters and 0.75 literof 60% acetic acid, 1 kg. of ammonium sulfate and 125 g. of the sodiumsalt of the acid sulfuric acid ester of an aduet of 1 mole of sperm oilalcohol and 80 moles of ethylene oxide are dissolved therein. 0.15 kg.of sodium pyrophosphate, 0.135 kg. of ethylenediaminotetracetic acid and8 liters of a stock bleaching solution consisting of:

Parts 35% hydrogen peroxide 65 Diethylformamide .c. 10 10% sulfuric acid15 Water 10 are also added to the liquor. Finally 50 g. of the dye usedin Example 7 is dissolved in water and added to the liquor and theliquor is made up to 1,000 liters with water. 50 kg. of unbleachedprecleaned woolen piece goods is introduced into the liquor, ten minutesis allowed to elapse to wet the goods, and the liquor is heated toboiling temperature within forty to forty-five minutes and left atboiling temperature for another forty to forty-five minutes. The liquoris then drained off and the good are rinsed in the usual way. Abeautiful bright pale grey dyeing is obtained on the goods.

I claim:

1. A process for simultaneously dyeing and bleaching proteinaceousfibers in an aqueous liquor under nonalkaline conditions, whichcomprises treating the fibers at an elevated temperature as required fordyeing wool in an aqueous liquor which has a pH-value of 1 to 7 andwhich contains (a) an acid dye capable of dyeing wool and resistant toperoxides, (b) performic acid, said performic acid being formed byreaction of hydrogen peroxide with a compound selected from the groupconsisting of compounds capable of splitting off formaldehyde under thereaction conditions, low molecular weight formic acid alkanol esters andlow molecular weight formamides, and (c) at least one oxygen stabilizerselected from the group consisting of magnesium phosphate, alkali metalpolyphosphates and complex-forming amino-polycarboxylie acids and theirammonium, alkali metal and alkaline earth metal salts, theamount ofactive oxygen initially available for said treatment being 0.2 to 10g./l. and the amount of said oxygen stabilizer being about 0.1 to 1times the weight of active oxygen initially available when using saidaminopolycarboxylic acids, their salts and mixtures as the stabilizerand about 2 to 30 times the weight of active oxygen initially availablewhen using only a phosphate stabilizer.

2. A process according to claim 1 wherein wool is simultaneously dyedand bleached.

3. A process according to claim 1 wherein performic acid is formed fromcompounds capable of splitting oil formaldehyde and ammonia.

4 A process according to claim 1 wherein performic acid is formed fromlow molecular weight formamide.

5. A process according to claim 1 wherein performic acid is formed byreacting hydrogen peroxide with hexamethylenetetramide.

6. A process according to claim 1 wherein performic acid is formed byreacting hydrogen peroxide with formamide. r

7. A process according to claim 1 wherein performic acid is formed byreacting hydrogen peroxide with dimethylformamide.

8. A process according to claim 1 wherein performic acid is formed byreacting hydrogen peroxide with hydroxymethane sulfonate.

9. A process according to claim 1 wherein performic acid is formed byreacting hydrogen peroxide with iminobis-methane sulfonate.

References Cited UNITED STATES PATENTS 3,363,970 l/1968 Schaffner 8-193,374,177 3/1968 Schmidtet al 252-186 FOREIGN PATENTS 1,032,260 6/1966Great Britain.

NORMAN G.TORCH1N, Primary Examiner .l. E. CALLAGHAN, Assistant ExaminerUS. Cl. X.R. 8-54 533 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,55 7 Dated December 29, 1970 Inventor(s) OswaldSchmidt C It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 9, in the heading, "1,469,607 should read Column 3, line75, delete the entire line.

Column 4, line 40, "alnaline" should read alkaline Column 6, line 52,"in" should read is Signed and sealed this Lrth day of May 1 971 (SEAL)Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, Atte sting OfficerCommissioner of Paton

